Cationic silicon (II) compounds are highly reactive compounds, which are of industrial interest owing to their electronic structure, especially for catalytic purposes. It could be shown, for example in Angew. Chem. 2011, 123, 6975, that the cationic Si (II) compound (C5Me5)Si+B(C6F5)4− catalyses the conversion of ethers with high selectivity.
In particular, the lack of synthetic accessibility has long stood in the way of the use of this compound class. The compound (C5Me5)Si+B(C6F5)4− can be prepared from silicocene, (C5Me5)2Si, —as described in Chem. Eur. Joc. 2014, 20, 9192—for example exclusively by reacting silicocene with the specific protic acid(C5H2Me5)+B(C6F5)4−, which is accessible only in a very complex, in part safety-critical 7-stage low temperature synthesis according to Organometallics 2000, 19, 1442 in connection with Science, 2004, 305, 849. Protic acids that are easier to access always result, as stated in J. Organomet. Chem. 1993, 446, 139, in oxidative addition with formation of an adduct with tetravalent silicon.
Thus, there is a need for a simpler method by which cationic silicon (II) compounds can be made accessible.